The Power of Vision: We See Not the World But a Simulation

Have you ever wondered about the capacity of the mammalian brain: its ability to make us aware of the external world? Consider, the power of sight. For example, consider the view of a well kept municipal garden with its ornamental trees and shrubs, its flower beds, its expanses of neatly clipped grass. What you see is out there. 

Right? 

No. Wrong. 

What you are "seeing" is a representation of what is out there that you brain has created based on images focused by the lens of the eye onto an array of light sensitive neurons, the rods and cones, that make up the eye's retina. It takes no more than a handful of photons striking one of these visual elements to initiate a neural impulse that travels via the optic nerve from the eye to the visual lobe of the brain. From thousands of such neural impulses received each second, the brain builds a model of the external world. 

And this is not a static model but a fast changing representation of the world as your attention darts from flower border, to grassy expanse, a passing cloud, a boy playing with a dog, a small child on a tricycle. It is the extraordinary realism of this model that leads to the mistaken belief that what we see is out there, whereas, in fact, what we "see" is a model of the external world created by the brain -- a model that includes ourself.